Method and system for managing the turning of a vehicle

ABSTRACT

A method and system for managing the turning of a vehicle comprises establishing a boundary of a work area. A location-determining receiver determines an observed position and velocity of the vehicle in the work area. An estimator estimates a first duration from an observed time when the vehicle will intercept the boundary based on determined position and velocity of the vehicle. An alert generator generates an alert during a second duration from the observed time. The second duration is less than or approximately equal to the first duration. An operator interface allows an operator to enter a command to control a path of the vehicle prior to or at the boundary.

This is a divisional application of U.S. application Ser. No.12/038,040, filed 27 Feb. 2008, issued as U.S. Pat. No. 8,131,432.

FIELD OF THE INVENTION

This invention relates to a method and system for managing the turningof a vehicle.

BACKGROUND OF THE INVENTION

Commercially available guidance systems may use Global PositioningSystems (GPS) to guide vehicles within a work area or field. Forexample, an agricultural vehicle may be equipped with a guidance systemto facilitate the alignment of different paths into a parallel series ofpaths with minimal overlap between adjacent paths. At the current time,it is typical for guidance systems to rely upon the operator of thevehicle to execute turns manually at the end of rows (e.g., in theheadlands of a field). Accordingly, there is a need to manage theturning of a vehicle at the end of rows in an efficient, safe andreliable manner.

SUMMARY OF THE INVENTION

A method and system for managing the turning of a vehicle comprisesestablishing a boundary of a work area. A location-determining receiverdetermines an observed position and velocity of the vehicle in the workarea. An estimator estimates a first duration from an observed time(e.g., a current time) when'the vehicle will intercept the boundarybased on determined position and velocity of the vehicle. An alertgenerator generates an alert during a second duration from the observedtime. The second duration is less than or approximately equal to thefirst duration. An operator interface allows an operator to enter acommand to control a path of the vehicle prior to or at the boundaryduring a control time window.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of one embodiment of a system for managing theturning of a vehicle.

FIG. 2 is a flow chart of one embodiment of a method for managing theturning of a vehicle.

FIG. 3 is a block diagram of another embodiment of a system for managingthe turning of a vehicle.

FIG. 4 is a block diagram of yet another embodiment of a system formanaging the turning of a vehicle.

FIG. 5 is a block diagram of still another embodiment of a system formanaging the turning of a vehicle.

FIG. 6 is an illustration of one possible configuration of an operatorinterface.

FIG. 7 is a flow chart of another embodiment of a method for managingthe turning of a vehicle.

FIG. 8 is a flow chart of another embodiment of a method for managingthe turning of a vehicle.

FIG. 9 is a flow chart of yet another embodiment of a method formanaging the turning of a vehicle.

FIG. 10 is a diagram of a vehicle executing illustrative turns at ornear a boundary.

FIG. 11 is a diagram of a vehicle executing illustrative turns at ornear an inner boundary within a headland.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In accordance with one embodiment and referring to FIG. 1, a managementsystem 11 for managing the turning of a vehicle comprises alocation-determining receiver 10 coupled to a data processor 12. Inturn, the data processor 12 is a capable of communicating with one ormore of the following: an operator interface 20, a data bus 26, a datastorage device 28 and a controller 34. The controller 34 is configuredto communicate with a steering system 36, a propulsion system 38 and abraking system 40.

The lines that are interconnecting the foregoing devices in themanagement system 11 may be physical data paths, logical data paths, orboth. Physical data paths are defined by transmission lines or databuses. Logical data paths may comprise logical or virtual communicationsthat take place within software or between software modules, orcommunications that occur over one or more data channels (e.g., timedivision multiplex channels).

The dotted line between the data bus 26 and the data storage device 28indicates an optional communications path 42 between the data bus 26 andthe data storage device 28. The optional communications path 42 may beused to support parallel processing or distributed processing ofmultiple tasks. For example, the data processor 12 or estimator 16 mayestimate the relative position of the vehicle with respect to a boundaryand may generate an appropriate alarm based on proximity of the vehicleto the boundary. Meanwhile, the controller 34 may generate (e.g.,independently) control signals or control data for executing one or moreturns of the vehicle, for controlling the propulsion system 38 of thevehicle, or for engaging the braking system 40 of the vehicle.

The location-determining receiver 10 comprises a Global PositioningSystem (GPS) receiver (e.g., a GPS receiver with differentialcorrection). The location-determining receiver 10 may provide one ormore of the following data types: position data (e.g., expressed asgeographic coordinates), velocity data, and acceleration data. Velocitydata further comprises speed data and heading data for the vehicle.

In one embodiment, the data processor 12 further comprises a boundarydefiner 14, an estimator 16, and an alert generator 18. The boundarydefiner 14 facilitates defining one or more boundaries of a work area orfield. For example, the boundary definer 14 may facilitate defining anouter boundary and an inner boundary of a work area. The boundarydefiner 14 may automatically generate an inner boundary based on anouter boundary of the work area and the turning radius of the vehicle,operator preferences, or otherwise.

The boundary definer 14 may define the boundary of the work area byrecording points along the boundary, by surveying the boundary, or by apre-existing map of the field or work area generated from a survey(e.g., ground or aerial survey) of the work area. For instance, if themanagement system 11 is located on a vehicle, as an operator traversesor tracks the boundary, inner boundary, or outer boundary of a workarea, the location-determining receiver 10 provides location data thatrecords the coordinates or points of the applicable boundary for storagein the data storage device 28 as boundary data 30. The data processor 12may later retrieve the boundary data 30 for a particular field or workarea to facilitate automated turning of the vehicle and provision ofoperator alerts prior to execution of such automated turning of thevehicle.

The estimator 16 is configured to provide an estimate (e.g., a temporalestimate) of when the vehicle will next cross a boundary (e.g., innerboundary or outer boundary) given the observed velocity and observedheading (e.g., where acceleration is approximately zero or a negligibleamount), or given the observed velocity, observed heading, andacceleration (e.g., current acceleration and estimated acceleration,which may be expressed as a curve, a differential equation or aquadratic equation). As used throughout this document, the termsobserved velocity and current velocity shall be regarded as synonymous;the terms current heading and observed heading shall be regarded assynonymous; and the terms observed acceleration and current accelerationshall be regarded as synonymous.

The alert generator 18 is configured to generate an alert signal or analert message that is triggered or initiated by the estimate being lessthan or equal to a threshold minimum time period. In one embodiment, analert signal or an alert message of the alert generator 18 may besustained or remain active after such triggering until the vehiclecrosses a boundary or approaches the boundary by a predeterminedtemporal amount or a predetermined distance. The predetermined temporalamount or predetermined distance maybe proportional to a speed orvelocity of the vehicle, for example. In another embodiment, the alertgenerator 18 may facilitate changing the volume, intensity, amplitude,frequency or other modulation of an audible alert, a visual alert, or anaudio visual alert based on the proximity of the vehicle to the boundary(e.g., inner boundary or boundary).

An operator interface 20 comprises a keyboard, a keypad, a display, apointing device (e.g., mouse or trackball), a switch, a console, or adashboard. In one embodiment, the operator interface 20 comprises aswitch 22 and an alert device 24. The alert device 24 may comprise anaudio alarm, a siren, a buzzer or another alert device for producing anaudible alarm or one or more tones. In another embodiment, the alertdevice may comprise an audio visual device for expressing an audible andvisual alert. In yet another embodiment, the alert generator 18 or thealert device 24 increases a volume, alters an amplitude, changes a pitchor frequency, or otherwise changes the modulation of the audible alert(e.g., a tone or group of tones) if the control time window expireswithout the operator entering the command. Similarly, if the alertdevice 24 comprises a display, the intensity of the display may bealtered, the image may be flashed, colors may be alternated, portions ofthe images may be rotated or moved, or other attention-grabbing imagesor visual tactics may be used.

The data storage device 28 may store boundary data 30 and turn data 32.The boundary data 30 may comprise outer boundary data, inner boundarydata or other boundary data that is relevant to a particular work areaor field. The turn data 32 may comprise generic turns for execution by avehicle or particular vehicle based on the characteristics of thevehicle, its associated implement, or both. The turn data 32 maycomprise right turn data, left turn data, bulb-shaped turn data,row-skipping turn data, arc turn data, arched turn data, U-turn data,headland turn data, or the like.

The controller 34 may comprise a control interface that provides aninterface between the data processor 12 and one or more of thefollowing: a steering system 36, a propulsion system 38, or a brakingsystem 40. In one example, if the steering system 36, propulsion system38, or braking system 40 accepts an analog input, the controller 34 maycomprise a memory buffer and a digital-to-analog converter. In anotherexample, if the steering system 36, propulsion system 38, or brakingsystem 40 accepts a digital input, a contact closure, or a logic levelsignal, the controller 34 may comprise a driver, a relay circuit, alogic level circuit, or a power switching circuit. In yet anotherexample, the controller 34 sends a digital or analog control signal(e.g., steering angle commands, heading commands, or position dataassociated with corresponding time data) to the steering system 36 toexecute an automated turn or a manually controlled turn at or near aboundary. In still another example, the controller 34 sends a digital oranalog control signal to the braking system 40 if the control timewindow expires without the operator entering a command.

The steering system 36 may comprise an electrical steering system, adrive-by-wire steering system, an electro-hydraulic steering system, ora hydraulic steering system with an electronic control interface. Anelectrical steering system or a drive-by-wire steering system maycomprise an electric motor or actuator that is mechanically coupled(e.g., via a rack and pinion gear coupled to a steering shaft) to rotateor steer at least one wheel of the vehicle. An electro-hydraulicsteering system may control a hydraulic valve, a hydraulic cylinder oranother hydraulic member via a solenoid or another electro-mechanicaldevice to steer the vehicle or execute a turn.

The propulsion system 38 may comprise an internal combustion engine, thecombination of an electric drive motor and motor controller, or a hybridwith both an internal combustion engine and an electric drive motor. Ifthe propulsion system 38 is an internal combustion engine, thecontroller 34 may interface with a throttle controller, a fuel injectionsystem, a carburetor, or another device for metering fuel, air, or thefuel-air mixture. If the propulsion system 38 is an electric motor, thecontroller 34 may interface with a motor controller, an inverter, achopper, an alternating current source, a signal generator, a variablevoltage supply, a variable current supply, or another device forcontrolling the operation of the motor.

The braking system 40 may comprise an electro-hydraulic braking system,an electrical braking system, or an electrically operated mechanicalbraking system. An electro-hydraulic braking system may control ahydraulic valve, a hydraulic cylinder or another hydraulic member via asolenoid or another electro-mechanical device to slow or stop thevehicle. An electrical braking system may convert mechanical rotationalenergy of the wheels into electrical energy through a generator oralternator associated with one or more wheels of the vehicle. Anelectrically operated mechanical braking system may use friction betweenbraking members (e.g., pads and a rotor, or shoes and a drum) that isactivated (e.g., via a solenoid) upon the receipt of a certain digitalor analog signal.

FIG. 2 illustrates a method for managing the turning of a vehicle. Themethod of FIG. 2 starts in step S100.

In step S100, a boundary definer 14 establishes a boundary of a workarea (e.g., field). For example, a boundary definer 14 establishes anouter boundary coincident with the perimeter of a work area and an innerboundary spatially separated from the outer boundary or from one or moresides of the outer boundary. Further, in one illustrative example, thezone between the outer boundary and inner boundary may comprise aheadland, where the work area is a field. The headland may represent anunplowed area at the end of a row in a field. Alternately, the headlandmay represent an area that is plowed, planted or harvested by making atleast one pass that is generally perpendicular to the other rows in thefield.

In step S102, at or prior to an observed time, a location-determiningreceiver 10 determines an observed position and an observed velocity ofa vehicle in the work area. For example, at or prior to an observedtime, the location-determining receiver 10 may determine an observedposition, an observed velocity and an observed acceleration of thevehicle in the work area.

In step S104, an estimator 16 or data processor 12 estimates a firstduration from an observed time (e.g., current time) when the vehiclewill intercept the boundary based on the determined, observed positionand observed velocity of the vehicle. For example, the estimator 16 ordata processor 12 estimates a first duration from a current time whenthe vehicle will intercept the boundary based on the determined observedposition, observed velocity and observed acceleration of the vehicle.The estimator 16 may use motion equations that assume no acceleration,nominal acceleration, a constant acceleration, or another accelerationmodel or representation, consistent with the vehicle, its propulsionsystem and the applicable task at hand. The acceleration model maydefine the acceleration as an acceleration versus time curve, or aquadratic equation representing the curve, or a look-up table ordatabase representing the curve. The first duration may represent theelapsed time from the observed time to a later time where a referencepoint (e.g., a leading edge or front) associated with the vehiclereaches the boundary.

In step S106, an alert generator 18 or a data processor 12 generates analert during a second duration. The second duration is less than orapproximately equal the first duration. For example, the second durationmay be less than the first duration by a processing time or estimationtime (e.g., 100 to 300 milliseconds) associated with the data processor12 estimating the first duration. In one embodiment, the second durationranges between approximately 10 to approximately 30 seconds, althoughother duration ranges can fall within the scope of the claimedinvention.

Step S106 may be carried out in accordance with various procedures thatmay be applied alternately or cumulatively. Under a first procedure, thealert comprises an audible alert. Under a second procedure, the alertcomprises an audible and visual alert. Under a third procedure, thealert comprises movement or vibration of a seat of the operator by anactuator 322 (e.g., a linear motor, a rotary motor capable of reversiblerotation, and an electro-hydraulic member, or an electrically-controlledpneumatic system).

In step S108, an operator interface 20 allows an operator to enter acommand to control a path of the vehicle at the boundary during acontrol time window. The control time window is a period of time that isallocated for the operator's entry of a command, confirmation, or otherinput into the operator interface. In a first example, the duration ofthe control time window may be commensurate with the velocity,acceleration and proximity or position of the vehicle with respect tothe nearest boundary. In a second example, the duration of the controltime window may be selected based on a stopping distance of the vehiclegiven its velocity, position, and mean or mode stopping distancecapability of its braking system 40. In a third example, the duration ofthe control time window may be selected based on a stopping distance ofthe vehicle given its velocity, position, load state (e.g., tare weight,gross weight and net weight).

Step S108 may be carried out in accordance with various techniques thatmay be applied alternately or cumulatively. Under a first technique, theoperator interface 20 allows an operator to enter the command to confirma preplanned or automated turn of the vehicle. Under a second technique,the operator interface 20 allows an operator to enter the command tochange a direction of turn from a right turn to a left turn, or viceversa. Under a third technique, the operator interface 20 allows anoperator to enter the command to skip rows, each row being commensuratewith a vehicle width of the vehicle. Under a fourth technique, theoperator interface 20 allows an operator to enter the command tooverride an automated turn by activating an override switch 22 in a cabof the vehicle. Under a fifth technique, the operator interface 20allows an operator to manually turn a steering wheel to elect a manualturning mode of the vehicle and to disable an upcoming automated turn ofthe vehicle, where a torque detector detects a threshold minimum torquelevel. Under a sixth technique, the operator interface 20 allows anoperator to manually turn a steering wheel to elect a manual turningmode of the vehicle and to disable an upcoming automated turn of thevehicle, where a rotation sensor 222 detects a minimum angular rotationof the steering wheel or its shaft. Under a seventh technique, theoperator interface 20 allows an operator to enter a command to controlthe vehicle to make a U-turn, an arched turn, or a row skipping turn.Under an eighth technique, the operator interface 20 allows an operatorto enter a command to control the vehicle to make a bulb-shaped turn.Under a ninth technique, the operator interface 20 allows an operator tosimultaneously generate an alert under step S106 and to enter a commandto control the vehicle under step S108.

The management system 111 of FIG. 3 is similar to the management system11 of FIG. 1, except the management system 111 of FIG. 3 replaces theswitch 22 with a torque sensor 122. The operator interface 120 comprisesthe torque sensor 122 and an alert device 24. In one embodiment, thetorque sensor 122 is associated with at least one of a steering shaft, asteering wheel, or the steering system 36 to detect whether the operatorof the vehicle applies a certain minimum torque level to the steeringwheel. If the operator applies a certain minimum torque level to thesteering wheel, the data processor 12 or controller 34 may interrupt orseize control of steering commands generated by or executed by thecontroller 34 to allow an operator to manually steer the vehicle via thesteering wheel. Accordingly, if the torque sensor 122 detects a certainminimum torque during a time period, the data processor 12 or controller34 overrides an automated steering mode in favor of a manual steeringmode. In the automated steering mode, the data processor 12 or thecontroller 34 steers the vehicle, via the steering system 36, through aturn in accordance with location data from the location-determiningreceiver 10 and turn data 32 that is stored in the data storage device28 or elsewhere. In the manual steering mode, the controller 34 mayallow an operator to manually steer the vehicle along a desired path, orto avoid an obstacle or take evasive action.

The management system 211 of FIG. 4 is similar to the management system11 of FIG. 1, except the management system 211 of FIG. 4 replaces theswitch 22 with a rotation sensor 222. The operator interface 220comprises the rotation sensor 222 and the alert device 24. In oneembodiment, the rotation sensor 222 is associated with at least one of asteering shaft, a steering wheel, or the steering system 36 to detectwhether the operator of the vehicle applies a certain minimum angularrotation to the steering wheel. If the operator applies a certainminimum angular rotation of the steering wheel, the data processor 12 orcontroller 34 may interrupt or seize control of steering commandsgenerated by or executed by the controller 34.

The management system 311 of FIG. 5 is similar to the management system11 of FIG. 1, except the management system 311 of FIG. 5 replaces theswitch 22 and the alert device 24 with an actuator 322. The operatorinterface 320 comprises the actuator 322. In one embodiment, theactuator 322 is operably connected to a seat or a seat component (e.g.,seat suspension member) of the vehicle and fixed portion (e.g., frame,structural member or supporting structure) of the vehicle. The seat maybe arranged so that it is movable with respect to the fixed portion byhinges or suspension members, for example. The actuator 322 may comprisea linear motor, the combination of a pneumatically charged cylinder andan air compressor, an electro-hydraulic cylinder controlled by anelectrical or electronic control signal, or a rotary motor (capable ofreversal of rotational direction) coupled to a belt or chain. The alertgenerator 18 sends a control signal or control data to the actuator 322for generation of an alert. In response to the control signal or controldata, the actuator 322 provides vibration, shaking, or other movement ofthe operator seat to warn an operator of approaching of a boundary ofthe vehicle to the control signal or control data. The management system311 of FIG. 5 is well suited for an operator that may be deaf, hearingimpaired, inattentive, not alert, drowsy, unconscious or sleepy Thus,the actuator 322 functions as an alert device for the operator.

FIG. 6 is an illustration of one possible configuration or display 600of an operator interface (20, 120, 220 or 320) that supports anoperator's entry of a command. In the exemplary configuration of FIG. 6,the operator may confirm the approaching turn by selecting or activatinga right turn arrow 601, a left turn arrow 603, or a straight arrow 605.As indicated by the cross-hatching, the right turn arrow 601 is selectedin FIG. 6 for illustrative purposes. The display 600 also provides anindication of a distance 607 between an observed position (e.g., currentposition) of the vehicle and the boundary or an inner boundary. The bellsymbol 609 in the lower right corner indicates that an audible alert oralarm is active, or will become active upon approaching the boundary,whereas a bell symbol with a diagonal line through it may indicate thatthe audible alert or alarm is inactive or deactivated.

The method of FIG. 7 is similar to the method of FIG. 2, except FIG. 7includes additional step S110. Like reference numbers in FIG. 2 and FIG.7 indicate like steps or procedures.

Following step S108, in step S110 a controller 34 or data processor 12stops the vehicle by controlling the braking system 40 after expirationof the control time window without the operator entering a command(e.g., to control the path of the vehicle or to confirm an automatedturn of the vehicle). If the operator fails to enter a command orconfirm the automated turn within the control time window, it mayindicate that the operator is inattentive or not alert. Similarly, ifthe operator fails to enter a command to control the path of the vehiclewithin the control time window, it may indicate that the operator isinattentive or not alert.

The method of FIG. 8 is similar to the method of FIG. 2, except FIG. 8includes additional step S112. Like reference numbers in FIG. 2 and FIG.8 indicate like steps or procedures.

Following step S108, in step S112 a data processor 12 or alert device 24increases a volume of an audible tone, changes a pitch (e.g., frequency)or modulation of the audible tone after expiration of the control timewindow without the operator entering a command (e.g., to control thepath of the vehicle to confirm an automated turn of the vehicle). If theoperator fails to enter a command or confirm the automated turn withinthe control time window, it may indicate that the operator isinattentive or not alert. Similarly, if the operator fails to enter acommand to control the path of the vehicle within the control timewindow, it may indicate that the operator is inattentive or not alert.

The method of FIG. 9 is similar to that of FIG. 2, except step S100 isreplaced with step S200 and step S114 is added.

In step S200, a boundary definer 14 establishes a boundary comprising aninner boundary and an outer boundary of a work area. For example, thezone or area between the inner boundary and the outer boundary maydefine a headland.

In step S102, a location-determining receiver 10 determines a positionand velocity of a vehicle in the work area. For example, thelocation-determining receiver 10 may determine an observed position, anobserved velocity and an observed acceleration of the vehicle in thework area.

In step S104, an estimator 16 or data processor 12 estimates a firstduration from an observed time (e.g., a current time) when the vehiclewill intercept the boundary based on the determined observed positionand velocity of the vehicle. For example, the estimator 16 or dataprocessor 12 estimates a first duration from an observed time when thevehicle will intercept the boundary based on the determined position,velocity and acceleration of the vehicle.

In step S106, an alert generator 18 or a data processor 12 generates analert during a second duration from the observed time. The secondduration is less than or approximately equal the first duration. Forexample, the second duration may be less than the first duration by aprocessing time or estimation time (e.g., 100 to 300 milliseconds)associated with the data processor 12 estimating the first duration. Inone embodiment, the second duration ranges between approximately 10 toapproximately 30 seconds, although other duration ranges can fall withinthe scope of the claimed invention.

Step S106 may be carried out in accordance with various procedures thatmay be applied alternately or cumulatively. Under a first procedure, thealert comprises an audible alert. Under a second procedure, the alertcomprises an audible and visual alert. Under a third procedure, thealert comprises movement or vibration of a seat of the operator by anactuator 322 (e.g., a linear motor, a rotary motor capable of reversiblerotation, and an electro-hydraulic member, or an electrically-controlledpneumatic system).

In step S108, an operator interface 20 allows an operator to enter acommand to control a path of the vehicle at the boundary during acontrol time window. The other aspects of step S108 that are set forthin the description of FIG. 2 apply equally here as if fully set forth inconjunction with FIG. 9.

In step S114, the data processor 12 or controller 34 controls thesteering system 36 to make an automatic bulb-shaped turn or arow-skipping turn between the inner boundary and the outer boundary. Forexample, the data processor 12 or controller 34 controls the steeringsystem 36 to execute an automatic bulb-shaped turn in the headland or arow-skipping turn in the headland.

FIG. 10 is a diagram of a vehicle 900 executing illustrative turns at ornear a boundary. A vehicle 900 is equipped with any of the systems(11,111, 211, or 311) described herein. The vehicle 900 operates in afield or work area 901 that is bounded by a first boundary 902 and asecond boundary 903. As illustrated in FIG. 10, turns are executedoutside of the first boundary 902 or the second boundary 903 at the endsof the rows or passes of the vehicle 900. The arrows indicate theillustrative direction of travel of the path of the vehicle 900.Although other paths are possible and fall within the scope of theclaims, the illustrative example of FIG. 10 shows the vehicle 900travels toward the first boundary 902 (e.g., in an upward direction onthe sheet) to make a first row-skipping turn 904 upon or after reachingthe first boundary 902. The vehicle 900 then travels toward the secondboundary 903 (e.g., in a downward direction on the sheet) where thevehicle 900 makes a first bulb-shaped turn 908 such that adjacent rows907 are covered by the vehicle 900 within minimal overlap (e.g., or atarget overlap) of an implement (e.g., cutter, mower, plow, planter,sprayer, scraper, harvester, or combine) associated with the vehicle900.

Upon or after the vehicle 900 reaches the first boundary 902, thevehicle 900 executes a second row-skipping turn 905 such that thevehicle 900 travels toward the second boundary 903 (e.g., in a downwarddirection on the sheet) after the turn. Upon or after the vehicle 900reaches the second boundary 903, the vehicle 900 executes a secondbulb-shaped turn 909 to facilitate coverage of multiple adjacentparallel rows 914. Next, the vehicle 900 progresses toward the firstboundary 902 where the vehicle executes a third row-skipping turn 906.Prior to execution of any of the foregoing turns, the operator has anopportunity to enter a command to execute a desired automated turn, amodification of a pre-programmed automated turn, or manual turn, aspreviously described in this document and the accompanying drawings.

FIG. 11 is a diagram of a vehicle 900 executing illustrative turnsbetween an inner boundary and an outer boundary 910, or betweenheadlands 912. A vehicle 900 is equipped with any of the systems(11,111, 211, or 311) described herein. The vehicle 900 operates in afield or work area 901 that is bounded by a first inner boundary 916 anda second inner boundary 918. Further, a headland 912 is defined by afirst zone between the first inner boundary 916 and an outer boundary910, and by a second zone between a second inner boundary 918 and anouter boundary 910. As illustrated in FIG. 11, turns are executed in theheadlands 912 at the ends of the rows or passes of the vehicle 900.Accordingly, in accordance with FIG. 11 the vehicle 900 and itsassociated implement, with their respective minimum turning radiioperate entirely within the headland without crossing the outer boundary910.

The arrows indicate the illustrative direction of travel of the path ofthe vehicle 900. Although other paths are possible and fall within thescope of the claims, the illustrative example of FIG. 11 shows thevehicle 900 travels toward the first inner boundary 916 (e.g., in anupward direction on the sheet) to make a first row-skipping turn 904upon or after reaching the first inner boundary 916. The vehicle 900then travels toward the second inner boundary 918 (e.g., in a downwarddirection on the sheet) where the vehicle 900 makes a first bulb-shapedturn 908 such that adjacent rows 907 are covered by the vehicle 900within minimal overlap of an implement (e.g., cutter, mower, plow,planter, sprayer, scraper, harvester, or combine) associated with thevehicle 900.

Upon or after the vehicle 900 reaches the first inner boundary 916, thevehicle 900 executes a second row-skipping turn 905 such that thevehicle 900 is traveling toward the second inner boundary 918 (in adownward direction) on the sheet after the turn. Upon or after thevehicle 900 reaches the second inner boundary 918, the vehicle 900executes a second bulb-shaped turn 909 to facilitate coverage ofmultiple adjacent parallel rows 914. Next, the vehicle 900 progressestoward the first inner boundary 916 to execute a third row-skipping turn906. In one embodiment, all of the turns shown in FIG. 11 are madewithin the confines of the headland 912 and do not go beyond the outerboundary 910. Prior to execution of any of the foregoing turns, theoperator has an opportunity to enter a command to execute a desiredautomated turn, a modified automated turn, or manual turn, as previouslydescribed in this document and the accompanying drawings.

Having described the preferred embodiment, it will become apparent thatvarious modifications can be made without departing from the scope ofthe invention as defined in the accompanying claims.

1-16. (canceled)
 17. A system for controlling the operation of avehicle, the system comprising: a boundary definer for establishing aboundary of a work area; a location-determining receiver for determiningan observed position and velocity of the vehicle in the work area; anestimator for estimating a first duration from an observed time when thevehicle will intercept the boundary based on the determined position andvelocity of the vehicle; an alert generator for generating an alertduring a second duration from the observed time, the second durationless than or approximately equal to the first duration; and an operatorinterface for allowing an operator to enter a command to control a pathof the vehicle at the boundary during a control time window, where theduration of the control time window is commensurate with the velocity,acceleration and proximity or position of the vehicle with respect to anearest boundary of the work area.
 18. The system according to claim 17further comprising: a braking system; a controller for sending a signalto the braking system if the control time window expires without theoperator entering the command.
 19. The system according to claim 17further comprising: an alert device for producing at least one audibletone; the alert generator increasing a volume or changing a pitch of theat least one audible tone if the control time window expires without theoperator entering the command.
 20. The system according to claim 17wherein the boundary comprises an inner boundary and outer boundary thatdefines a headland and further comprising: a controller for executing anautomatic bulb-shaped turn in the headland.
 21. The system according toclaim 17 further comprising an alert device for producing an audiblealert.
 22. The system according to claim 17 further comprising an alertdevice for expressing an audible and visual alert.
 23. The systemaccording to claim 17 further comprising: an actuator; the alertgenerator arranged to generate a signal for causing movement of a seatof the operator by the actuator.
 24. The system according to claim 17wherein the duration of the control time window is selected based on astopping distance of the vehicle given its velocity, position, and loadstate.
 25. The system according to claim 17 wherein the duration of thecontrol time window is selected based on a stopping distance of thevehicle given its velocity, position, and weight.
 26. The systemaccording to claim 17 wherein the duration of the control time window isselected based on a stopping distance of the vehicle given its velocity,position, and mean or mode stopping distance capability of its brakingsystem.